Black Thunder Mine process improvement director Steve Beil observed a mine wall. Black Thunder produced more coal than any single mine in the nation last year.
Photo by Walter Cook
Biggest of the BIG
Black Thunder Mine top coal producer again
By Walter Cook
Staff Writer
It may not have the splendor of a mountain canyon, but it’s got the size of one.
Welcome to Thunder Basin Coal Co.’s Black Thunder Mine — the most productive surface coal mine in the world.
More than one-fifth of the coal shipped out of the Powder River Basin in 2006 — 92.5 million tons — came out of Black Thunder, an extra-impressive feat considering the basin contains the largest known coal deposit in the world.
In all, a record-breaking 444.9 million tons of coal shipped out of the Powder River Basin in 2006.
Black Thunder’s closest rival last year was the Powder River Coal Co.’s North Antelope/Rochelle Mine, which shipped out 88.5 million tons. Black Thunder reclaimed its crown as the king of coal starting in 2004, following a brief stint of finishing second to North Antelope/Rochelle.
Thunder Basin Coal, a subsidiary of Arch Coal, is able to extract so much of the black stuff out of the ground at Black Thunder thanks to its heavy duty fleet, including one of the biggest machines in the business: Ursa Major, a Bucyrus-Erie 2570WS dragline capable of picking up 164 cubic yards of earth in a single scoop.
Its shovel, as pointed out proudly by Black Thunder’s director of process development Steve Beil, has the same capacity of an overburden haul truck, which typically carries 240 tons per load.
The metal beast, powered by eight electric motors fed by a several-inch diameter power cord, runs 24 hours a day, seven days a week.
At the end of a typical day, Ursa Major will have displaced 114,000 cubic yards of earth. It will have taken just two operators at the helm on two different shifts to do the job.
Earth is known as “overburden” in the mining business, likely because you have to burden yourself with it before you can get to the good stuff — in Ursa Major’s case: coal.
Ursa Major is essential to the Black Thunder fleet as the mine’s 68-foot coal seam generally is covered by 200 feet of overburden, according to Beil.
Shovels and haul trucks could certainly do the job — and they do in other parts of the massive mine — but it would take a lot longer.
As big as they are — an overburden truck tire is nearly 20-feet high — trucks and shovels look like toys when situated next to Ursa Major, which looks to have the surface area of a city block.
But the metal behemoth couldn’t do its job alone. In fact, if it weren’t for the crews initially on the scene, driving around in mobile drilling units just a fraction of the size of the dragline, Ursa Major wouldn’t be able to do its job at all.
The machine, for all its raw power, is only able to move dirt because the dirt is soft, which, in the mining business, can mean only one thing: it was blown up.
The crews who drill holes in the overburden are the blasters. Each hole they drill holds an explosive mixture of ammonium nitrate and diesel fuel.
The typical overburden blast contains about 200 such volatile holes.
Those in the explosives industry, such as Bobby Ingram of Nelson Brothers Mining Services, say surface mining blasts are complex; it’s not just a matter of “blowing things up.”
According to Black Thunder’s blasting experts, blasts are so precise that about one-third of the overburden is moved to its final destination during the blast, where it will be used for reclamation.
Thanks to the view offered inside the ironically small cab of Ursa Major, operated by Mike Waldner, the precision involved in blasting became apparent.
The first-person view of the dragline’s massive bucket dropping into the dirt was impressive in itself, but to see an explosion knock loose the coal seam below, while atop the machine, was awe-inspiring.
Construction through destruction.
The blast took mere seconds. Afterward, a cloud of black dust enveloped the dragline, but that didn’t stop Waldner, who continued to move the machine with unwavering accuracy using a lever that looked as though it belonged on a video game system: move left to pivot left, move right to pivot right, up to lower bucket, down to hoist bucket.
From the cab, the ride was smooth, but 360 feet up, at the end of the boom, things were moving at 60 mph.
Developments
A new coal crusher, which breaks the stuff down so it can be transferred via a conveyer to the mine’s silos, was put together in January, according to Beil.
He said this was done because the mine has moved two miles to the west over the years, which put the old
crusher too far away. Open-pit mines in the Powder River Basin constantly are evolving: as coal is removed from one area, mining begins in another, while, at the same time, reclamation takes place over the depleted portion of the mine, with the operators required to form the dirt at the same slope that existed before mining operations began.
The new crusher was a big investment for the mine, but it was well worth it, according to Beil.
“Anything we can do to shorten the distance to haul material has big dividends,” he said.
Tire life was a consideration in the project, Beil said, as competition with China for materials has made tires scarce.
The shorter the distance the trucks have to drive, the less likelihood that a tire will be damaged, he said.
With coal and overburden haul truck tires going for $20,000-$100,000, Beil called tire maintenance a “major focus” of Black Thunder Mine.
Black Thunder Mine has been operational since 1977.
All hail the king
Wyoming mines shipped 444.9 million tons in ’06
By Walter Cook
Staff Writer
GILLETTE — On State Highway 59 between Douglas and Gillette, it is hard to tell much is going on in this place. From here, all that decorates the green, rolling hills are the occasional old farmhouse and the many miles of criss-crossing barbed wire fences.
But get off the main drag and head east about 10 miles, and the serene environment gives way to bustling economic activity.
With ant-like precision, massive haul trucks equipped with tires nearly 20 feet high reclaim the land they had been responsible for disturbing just months ago, and draglines with booms as long as a football field plunge into the earth like big dippers, picking up 100 tons of dirt at a time.
Once the earth or, as it’s known in the mining industry, “overburden,” is removed, the miners find what they were looking for — coal.
Not that their search is a hard one — Wyoming’s economy is stoked by the stuff. Campbell County alone is responsible for nearly 35 percent of the nation’s annual coal production, which fuels roughly 15 percent of the nation’s energy demands.
For this reason, Campbell County (as well as a fraction of southern Converse County) is known as the Saudi Arabia of Coal, with more than 400 million tons of it extracted from the area annually.
Geologists say the fantastic Powder River Basin coal seam stretches all the way from the Gillette and Wright area to the Bighorn Mountains in southern Montana, about 100 miles away.
Wyoming contains the top 10 producing coal mines in the world — with nine of them located in Campbell County. Not only is Wyoming’s coal abundant, but it’s also closer to the surface, making mining for it more efficient compared to most places.
According to the U.S. Energy Information Administration, mining companies operating in Wyoming’s Powder River Basin can extract 75,000 tons more coal per employee than from mines in the eastern United States.
Thunder Basin Coal Co.’s Keith Williams, who recently relocated from Texas to manage Coal Creek Mine, has first-hand knowledge of the difference in eastern coal compared to Wyoming coal.
“This is clearly the best coal deposit in the United States,” Williams said of Wyoming’s black bounty.
Williams said it is not unusual for mining operations in eastern Texas to remove 150 feet of overburden to get access to a five-foot coal seam, a ratio of 30:1. In the Powder River Basin, he said, the ratio of overburden to coal ranges from 4:1 to 2:1.
The bottom line, according to Williams, is Wyoming coal is “cheaper (to extract), cleaner, and there’s a lot of it.”
The big players in the Powder River Basin — Peabody Energy, Rio Tinto Energy America, Arch Coal, Foundation Coal West and Kiewit Mining Group — combine to extract more than 400 million tons of coal year and provide thousands of jobs in the process.
Severance taxes from the state’s coal are the primary contributor to Wyoming’s Permanent Mineral Trust Fund, the interest from which helps fund state government.
Wyoming has been the top coal-producing state since 1988.
